The present invention relates to the field of evaporative cooling systems. More specifically, the present invention relates to an evaporative cooling apparatus that utilizes fresh water to control a buildup of mineral deposits in the apparatus.
Evaporative coolers are used in a variety of settings including factories, warehouses, workshops, and agricultural structures, as well as in homes and offices. Evaporative coolers are an attractive alternative to conventional air conditioning and mechanical refrigeration systems because they require minimal parts, are relatively simple to manufacture and maintain, are inexpensive to operate, and do not use ozone damaging refrigerants.
Generally, a evaporative cooling apparatus includes a large fan and water-wetted pads, also known as cooling media, mounted perpendicular to an outside air stream. Water is drawn from a sump and distributed over the top of the cooling media where the water flows down through the cooling media back to the sump. The cooling media absorbs some of this water producing a water field in the path of the outside air stream. The fan draws the outside air through the cooling media, which cools the air through the evaporation of the water in the cooling media, and blows the cooled air into the house. The evaporative cooler also slightly increases the humidity of the entering air. The cooling media on an evaporative cooler is a fairly efficient air filter, trapping particles on the wet surface. A continuous wetting of the cooling media flushes the trapped particles into the sump, or reservoir, below the cooling media.
Evaporative coolers rely on the efficiency of the cooling media to obtain maximum performance. Unfortunately, minerals supplied in the water will concentrate in the sump and eventually begin to create mineral deposits, also known as scale on the cooling media. The scale buildup in the sump can also undesirably affect the wet components, such as the recirculation pump. Thus, these deposits can severely degrade the efficiency of the cooling media and other wet components, shorten their useful life, and increase the cost of maintaining the evaporative cooler. In addition, scale can trap biological organisms and other organic materials that produce odors, provide a medium for the growth of bacteria and molds, and cause other negative effects.
A technique sometimes used to manage scale in an evaporative cooler is to periodically use acid treatments to dissolve the scale. Although acid will dissolve some of the scale, the acid has the undesirable affect of increasing corrosion in the evaporative cooler. Another technique is to frequently replace the cooling pads and physically scrape and remove scale from the cooler. This can become expensive and quite time consuming. As such, neither of these techniques is considered acceptable.
Some evaporative coolers are manufactured with a bleed-off system that continuously leaks a small quantity of water from the water distribution system in order to dilute mineral concentrations in the water in the sump. Unfortunately, even with the use of a bleed-off system, scale still forms at the point of greatest evaporation, that is, on the cooling media. Other evaporative coolers come with a sump dump, or blow-down system, that periodically dumps the water from the sump while the cooler is being operated. A blow-down system is useful in dusty areas, because it cleans the sump of filtered dirt and particles. Unfortunately, like the bleed-off systems, scale still forms at the point of greatest evaporation, that is, on the cooling media.
The problem of scale buildup is exacerbated in evaporative coolers used for cooling large industrial settings, such as warehouses, factories, agricultural structures, and so forth. These industrial evaporative coolers typically deliver an air volume of 10,000 cubic feet per minute (CFM) or higher, drawn through cooling media that may be eight to thirty-six inches thick. This is in contrast to residential evaporative coolers that typically deliver an air volume of 3300 CFM, 4500 CFM, or 6500 CFM, drawn through cooling media that is less than eight inches thick.
The greater cooling requirements of industrial evaporative coolers cause industrial coolers to evaporate significantly more water than their residential counterparts. As such, scale buildup on the cooling media is greatly increased. Unfortunately, component replacement and labor costs associated with repairing an industrial evaporative cooler are much greater then that of residential coolers. The costs are much higher due to the large housing size, the large cooling media, the high air draw fans, and the high water volume recirculation pumps needed to produce cooled air at air volumes in excess of 10,000 CFM.
Accordingly what is needed is an evaporative cooling apparatus that effectively controls the buildup of scale on the cooling media in order to maintain maximum cooling efficiency of the cooling media and to reduce costs associated with maintenance and repair of the evaporative cooling apparatus.
Accordingly, it is an advantage of the present invention that an evaporative cooling apparatus is provided.
It is another advantage of the present invention that an evaporative cooling apparatus is provided that effectively controls the buildup of mineral deposits on the cooling media.
It is another advantage of the present invention that an evaporative cooling apparatus is provided that may be used in industrial settings.
Yet another advantage of the present invention is that an evaporative cooling apparatus is provided that is cost effective to maintain and repair.
The above and other advantages of the present invention are carried out in one form by an evaporative cooling apparatus. The evaporative cooling apparatus includes a housing having an air entry side, an air exit side, and a sump. Cooling media is contained in the housing. The cooling media has an air inlet portion and an air outlet portion, the air inlet portion being adjacent the air entry side of the housing. A fresh water delivery system delivers fresh water to the air inlet portion of said cooling media, and a recirculated water delivery system delivers sump water from the sump to the air outlet side of the cooling media. A fan section proximate the air exit side of the housing draws air through the air entry side of the housing and into the cooling media from the air inlet portion through the air outlet portion to cool the air.